This invention relates to edible plastic fat-continuous emulsion food spreads, including margarine, and shortenings and their preparation, particularly for but not exclusively for culinary use.
For whatever purpose it is intended, whether for eating directly as a spread or for culinary purposes such as confectionery or baking purposes, similar requirements prevail for the fat component of margarine, in particular with regard to plasticity and spreadability. The aim is to provide high emulsion stability, wide plasticity range as little temperature-dependent as possible, and suitable consistency. These two last requirements are determined by a variety of considerations including choice of fat and glyceride oils, and cooling and working processes both of which affect these requirements through the crystal structure of the solidified glycerides of the fats and oils. The fat composition of margarine generally includes a glyceride oil or base stock which is retained in the products in the crystal matrix provided by a harder fat component or hard stock. For culinary purposes certain particular requirements are emphasised for example high creaming power while others such as eating quality decline correspondingly in importance, although it remains a relevant factor. For pastry fat on the other hand, high creaming power is less important than shortening power. The keeping quality of the margarine used is also important in baked goods and the fats and oils present must therefore be resistant to oxidation as far as possible. More recently, health considerations have imposed the additional requirement of a fatty acid residue in the glycerides constituting the fats and oils used, which combines high polyunsaturation i.e. a high combined linoleic acid content, with low saturated and trans acid content. To meet this requirement vegetable oils must be used in the base stock with an Iodine Value of at least 75.